The present invention relates generally to electric connectors and, more particularly, to an interference inhibiting, electric connector for use in high frequency data communications or the like.
Conventional jack connectors for data communications are characterized by a dielectric housing with a series of contacts positioned within the housing in relatively close proximity to one another. The jack contacts establish electrical connection between a corresponding wire conductor at one end of the contact and plug contacts and circuits on a printed circuit board on which the jack is mounted.
In locating the contacts in relative proximity to one another, especially during high performance communications, the contacts themselves become antennae for both broadcasting and receiving electromagnetic radiation. This leads to signal coupling between different pairs of contacts, a phenomenon commonly known as crosstalk. Crosstalk is a source of interference, characterized quantitatively by a signal-to-noise ratio that degrades the processing of incoming signals. As the frequency of interfering signals due to crosstalk and associated error rate increases, namely, during high performance communications, crosstalk becomes increasingly significant, often interfering with and otherwise obstructing data transfer.
Efforts have been made to reduce and even eliminate crosstalk in a variety of electrical applications. Of particular importance, in recent years, has been crosstalk reduction during high speed, high volume data transmission between wireless devices, computers or the like, especially in data streaming and video conferencing applications. Methods for reducing crosstalk have ranged from placement of the contacts in a crossed configuration to altering the geometry of the contacts themselves. Exemplary techniques include reverse-mounting and superimposition of the contacts, such as shown generally in U.S. Pat. No. 5,626,497, non-contact overlapping and cross-over of contact-pairs, as provided in U.S. Pat. No. 5,362,257, as well as twisting of the contacts with one another.
Geometric variation of the connector structure has also been found helpful in compensating for and/or substantially cancelling crosstalk. Such approaches include minimizing the surface area of contact blades and altering the contacts' placement relative to one another. An example of this approach is provided in U.S. Pat. No. 5,586,914.
Still another geometry-related construction for reducing crosstalk, namely, between contacts of two signal pairs, is to form capacitive couplings between the contacts of different signal pairs by utilizing extensions that extend laterally from the respective contacts. For example, U.S. Pat. No. 5,547,405 shows a crosstalk suppressing connector with two pairs of signal-carrying contacts. Each secondary contact is capacitively coupled to an initial contact of the other pair by a lateral extension formed in one of the contacts which overlies the other contact in a local region of limited length. This arrangement has also been found beneficial for crosstalk reduction.
Another approach to crosstalk mitigation has been to sever signal paths of selected connector contacts, then re-route them through a filter circuit in order to balance mutual inductance. Balancing inductance is a known crosstalk reducer. Illustrations of such techniques are set forth, for instance, in U.S. Pat. Nos. 5,470,244 and 5,454,738. Other useful techniques include the placement of dielectric spacers or inserts between contacts within the housing. Representative applications of insulation displacement connectors and dielectric inserts for crosstalk reduction may be found in U.S. Pat. Nos. 5,226,835 and 5,571,035, respectively.
Although prior attempts at crosstalk reduction have met with some success, they have been found not only difficult and costly to implement, but also of limited durability and reliability. Moreover, with the ever increasing speed of data communications, crosstalk produced at electric connections has intensified, necessitating further advances in crosstalk inhibition technology.
An electric connector is, therefore, desired that provides high performance data communication, that is simple and economical to produce, and that facilitates optimum data transfer with increasing frequency of transmission without signal degradation due to crosstalk.